With inevitable trends that wireless communication spectrum resources become increasingly inadequat and data transmission rates become increasingly high, a 60 GHz band wireless short-range communications technology attracts increasing attention and becomes one of technologies having the greatest potential among wireless communications technologies. The 60 GHz band wireless short-range communications technology is a millimeter-wave communications technology and has an enormous communication capacity. Moreover, the 60 GHz band is also a globally free band, and therefore the European countries, the United States, Japan, and the like successively obtain continuous non-licensed spectrum resources through division from a range of 57 GHz to 66 GHz.
Because a 60 GHz millimeter wave is applicable to high-speed, short-range line of sight (Line of sight, LOS for short) communication, an LOS communication link is an optimal path of communication between devices. When the LOS communication link is being blocked, the link is interrupted, causing a loss of data transmitted between the devices. After the LOS communication link is blocked, beam tracking is performed again between the devices to find another backup link (for example, a non line of sight path (Non Line of sight, NLOS for short)), and communication keeps taking place by using the backup link. When the backup link is also blocked or beam training needs to be performed again between the devices, a system finds the original optimal path again. Because switching of an optimal link and the backup link cannot be performed between the devices in time, a throughput of the entire system is obviously affected.